Counterbalanced drop end door assembly

ABSTRACT

A counterbalanced drop end door assembly for railway gondola cars combining a spring-counterbalanced, bottom-hinged drop end door and laterally acting latches mounted on the upper portion of the door and engageable with pluralities of ramped stops fixed to opposite sides of the car body along their paths of movement for selectively holding the door in any of a plurality of angularly related positions.

United States Patent Inventor Walter L. Floehr Toledo, Ohio Appl. No. 802,825

Filed Feb. 27, 1969 Patented Oct. 5, l 97 l As'signee Midland-Ross Corporation Cleveland, Ohio COUNTERBALANCED DROP END DOOR ASSEMBLY 8 Claims, 8 Drawing Figs.

US. Cl 105/406 A Int. Cl .8611! 17/00, B6ld 25/00 Field of Search 105/4065,

[56] References Cited UNlTED STATES PATENTS 2,506,218 5/1950 Ingram 105/406 (.5) 3,421,262 1/1969 Floehr 49/386 Primary ExaminerDrayton E. Hoffman Attorney-Wilmer Mechlin ABSTRACT: A counterbalanced drop end door assembly for railway gondola cars combining a spring-counterbalanced, bottom-hinged drop end door and laterally acting latches mounted on the upper portion of the door and engageable with pluralities of ramped stops fixed to opposite sides of the car body along their paths of movement for selectively holding the door in any of a plurality of angularly related positions.

| l I l l PATENTEDBBT 5m SHEET 1 OF 3 Inventor: Walter L. P10 8 hr 3 Bywa ullllld FIG. 1

his Attorhcy PATENTEDDCT sum 10,170

sum 2 or 3 Inventor:

Walter L. Floehr his Attorney FIG. 2 v

COUNTERBALANCED DROP END DOOR ASSEMBLY BACKGROUND OF THE INVENTION While it is not uncommon to provide drop-end doors of railway gondola cars with torsion bar or other spring counterbalances for retarding opening and assisting closing, it is difficult to conform the spring force to the door load over the range of movement of the door. As a result, except when locked in closed position, a counterbalanced door tends to move under the opposing forces of gravity and the counterbalancing spring out of any other position to which it is moved, even when fully opened, is unstable in position unless the gravity force then overbalances the spring force. Too, in previously proposed applications of counterbalancers to dropend doors, there has been no safeguard against injury to personnel or damage to the door or the car body in opening operation in case of failure of the counterbalance. It is to these problems that the present invention is particularly directed.

SUMMARY OF THE INVENTION The primary object of the present invention is to provide an improved counterbalanced drop-end door assembly whereby the door is positively holdable in open position regardless of the relation in that position of the opposing forces of gravity and the counterbalance. Another object of the invention is to provide an improved counterbalanced drop end door assembly which not only enables the door to be positively held in open position but also effectively safeguards against injury to personnel or damage to equipment in an opening operation in case of failure of the counterbalancers.

In the preferred embodiment of the invention, the drop-end door of the assembly is, as usual, hinged at the bottom for swinging from a vertical closed position inwardly to an open position substantially parallel to the floor of the car and is restrained in opening and assisted in closing by cushion bars anchored at opposite ends to the door and the car body. A pair of laterally acting, spring-pressed latches are mounted on and nonnally project from opposite sides of the upper portion of the door, each for engagement with a plurality of stops fixed to the corresponding side of the car body as spaced along the latches above the path of swinging movement, each stop having a ramp leading to its stop surface. The preferred assembly has on each side a pair of oppositely facing stops, each laterally aligned with a stop on the opposite side, one an intermediate stop facing outwardly for holding the door in its intermediate position and the other a bottom stop facing downwardly for holding the door in open position. Depending upon the construction, the assembly may include on each side an upper ramp leading inwardly from the side toward a recess or other suitable catch, for enabling the latches either to hold or assist in in holding the door in closed position.

Further objects and features of the invention will appear hereinafter in the detailed description, be particularly pointed out in the appended claims and be illustrated in the accompanying drawings, in which:

FIGURE DESCRIPTION FIG. 1 is a rear elevational view of a preferred embodiment of the improved counter drop-end door assembly of the present invention, with portions broken away and shown in section to more clearly illustrate certain of the details of construction;

FIG. 2 is a vertical sectional view taken along lines 2-2 of FIG. 1;

FIG. 3 is a fragmentary horizontal sectional view on an enlarged scale taken along lines 19-15 of FIG. 1;

FIG. 4 is a vertical sectional view taken along lines 44 of FIG. 3;

FIG. 5 is a vertical sectional view taken along lines 5-5 of FIG. 3;

FIG. 6 is a fragmentary horizontal sectional view of the door taken on the same section as FIG. 3, but on an intermediate scale and with the latch removed;

FIG. 7 is a fragmentary rear elevational view taken along lines 7-7 of FIG. 6; and

FIG. 8 is a fragmentary end elevational view taken along lines 88 of FIG. 7.

DETAILED DESCRIPTION Referring now in detail to the drawings in which like reference characters designate like parts, the improved counterbalanced dropend door assembly of the present invention is designed for application to a drop-end door I of a railway gondola car 2, which, conventionally, is mounted at an end of the car and bottom hinged or pivoted to a side 3 of the car body 4 for swinging, hinging or pivoting from a vertical posi-. tion closing that end inwardly to an open position in which it is substantially horizontal and parallel to the floor side of the body.

As exemplary of installations of drop-end doors, the illustrated door 1 is hinged to or pivotally mounted on corner posts 6 at opposite sides of the related end opening 7 and forming the adjoining end of the bodys sides 3. Suitably, the hinged mounting is obtained by fixing to the insides of the corner posts 6 adjacent the bottom of the opening 7, a pair of body brackets or hinge members 8, to which are connected for hinging or pivoting about a common horizontal axis a pair of door brackets or hinge members 9 fixed to opposite sides of the door 1.

Spring counterbalanced for retarding opening and assisting closing to permit one man operation, the door I conveniently has as its spring counterbalancer 10 a torsion bar arrangement similar to that shown in Goodwin U.S. Pat. No. 2,769,406, issued Nov. 6, l956. Thus, as in that patent, each body bracket 8 has an instanding cylindrical boss 11 rotatably received or seated in a cylindrical socket I2 in the adjoining door bracket 9 and the counterbalancer I0 is formed by two sets of torsion bars 13 centered on or concentric with the doors hinging axis and together extending laterally parallel across the door and through the sockets I2 and bosses 11. Housed for protection from the elements between the door bracket 9 by a housing 14 formed in the bottom portionv of the door and opening at opposite ends onto the sockets 12, each set of the torsion bars I3 is anchored at its outer end in a slot 15 in the adjoining body bracket 8 and at its inner end in the adjoining of a pair of oppositely opening slots 16 in a common door anchor member 17 mounted in the housing 14 intermediate the latters ends. Initially rotatable within limits by applying force to an integral lug 18 upstanding through a circumferentially extending slot 19 in the housing 14 for pretorsioning the bars I3 as necessary for a particular installation, the anchor member 17 thereafter is locked in place by welding the housing slot closed about the lug.

As pointed out in my U.S. Pat. No. 3,421,262, issued .Ian. 14, 1969, the load curve of a drop-end door, as it swings between open and closed positions, is a sine curve, while the torsional force developed by a conventional spring counter balance, such as shown in the Goodwin patent, is a straight line. Short of a relatively elaborate arrangement, such as shown in that application, only a rough approximation of the door load is obtainable in the opposing spring force and the best overall approximation, derived from a preset of about 5, produces a spring force in excess of the door load at full open position. Consequently, at least with conventional spring counterbalancing, except when it is locked in closed position by conventional locks (not shown) with its face or front 20 hearing against overlapping flanges 21 instanding from the sides 3 of the car body 4, the door has position stability only at the points at which the straight line of the spring force intercepts the sine curve of the door load. In minimizing the force required to be exerted by an operator in closing the door, the use of conventional spring counterbalancing therefore runs the risk of injury to personnel, particularly during unloading in the door's open position. This problem the improved assembly of the present invention solves by combining with the spring The preferred safety device 22 is comprised of a pair of laterally disposed latches 23 mounted adjacent opposite sides on the upper portion of the door 1 and having plungers 24 retractable within and yieldable, urgeable or projectable beyond opposite sides of the door, each by a spring 25 reacting against the door.

As its cooperating body-mounted components, the safety device 22 has fixed to and instanding from each of the side sheets 26 forming the sides 3 of the body 4 inwardly or rearwardly of the comer posts 6, at least one and preferably a plurality of catches or stops, each laterally aligned with a companion catch on the opposite side and in and, if a plurality, spaced along the arcuate path of movement of the adjoining plunger 24 as it swings with the door between closed and open positions. The minimum is a bottom or lower catch 27 on each side and the preference, another upper or intermediate catch 28 spaced along the adjoining plungers path of movement above and toward the adjoining end of the car body from the bottom catch. Each of the catches 27 and 28 has a flat stop surface or shoulder 29 instanding laterally from and normal to the related side sheet 26 and a ramp 30 leading inwardly from the side sheet toward that surface for engagement, respectively, with the side and end of the adjoining plunger 24, and the catches are oppositely facing or directed, the bottom downwardly and the upper outwardly toward the adjoining end of the car body. The downwardly facing bottom catches 27 are positioned adjacent the inward extremities of the paths of movement of the plungers 24 so as to present their stop surfaces 29 for engagement by the plungers in the doors open position and thus enable the door to be positively locked or held in that position. Conversely, the outwardly facing upper catches 28 served by their stop surfaces 29 either to stop the door in partly open position in case of failure of the spring counterbalancer or to hold the door in that position in transit to suit sometimes encountered special loading conditions. In addition, the ramp 30 on each, by presenting itself for engagement with the end of the adjoining plunger when the latter is projected, enables the operator by releasing the plunger after clearing either stop surface, to retard correspondingly, the swinging of the door. With the side sheets 26 outset relative to the comer posts 6, the illustrated assembly adds to the catches 27 and 28 on each side a top or third ramp 31 fixed to and extending inwardly from the adjoining side sheet onto the adjoining corner post and, if desired, that ramp also can have or lead to an outwardly facing stop surface (not shown) for enabling the plunger to hold or assist in holding the door in closed position.

As shown in FIGS. 3-8, each of the preferred latches 23 conveniently extends into and is mounted in part in one of the laterally extending depressions or concave convolutions 32 formed by the usual corrugated or so-called Dreadnaught" construction in the front of the door and has as its door reactants a strap or bracket 23 welded or otherwise fixed or secured to the door and itself fixedly mounting a guide or centering pin 34 for the coil spring and an encircling washer 35 backing the spring and, with the strap 33, acting as a stop for limiting retraction of the plunger 24.

Concentric with the guide pin 34, the plunger 24 slides or is slideably housed in an open-ended, preferably cylindrical, tube or tubular housing 36 seated and fixed, as by welding, in a slot 37 in the door and extending and opening from the depression 32 onto the side of the door through the latters rearwardly turned side flange 38. The plunger 24 cdnveniently has a cylindrically tubular body 39 slideably fitting or received in and longer than the housing 36 and opening at its inner end toward thefixed reactance member or abutment 33 for receiving the spring 25 and'projecting part of the guide pin 34 encircled thereby, while being closed or plugged at its outer end by a fixed plug 40 pressed against by the spring and also reinforcing the outer portion of the body. A handle 41 fixed to and outstanding from the inner end of the plunger 24 between the washer 35 and housing 36 pennits the plunger to be manually retracted against the force of the spring and is engageable with the confronting end of the housing for limiting the plunger's projection to clear the entrance ends of the ramps, while having a range of movement predetermined to accommodate movement of the plunger between full projection and retraction in the housing.

With the improved assembly, an operator in an opening operation will first unlock the door from the usual locks (not shown), then press inwardly against the door, at the same time retracting the plungers 24 if used as a secondary lock, but only until the door is unlocked therefrom. Continued inward pressure on the door with the plungers free to project, will swing the door inwardly to the intermediate or partly opened position at which it is stopped by engagement of the plungers with the stop surfaces 29 on the upper catches 28. Having had ample opportunity in the interim to determine by the pressure required whether the spring counterbalance 10 is operative, the operator without calling for additional help if he so finds, will retract the plungers to free them from the catches, but, with the limit imposed on that projection, need not hold them retracted as the door continues its swing, since they will automatically ride down the ramps 30 of the upper catches and subsequently up those of the lower catches and project on leaving the latter into locking engagement with the stop surfaces 29 on the lower catches as the door reaches open position. Thereafter, until disengaged from the lower catches to permit the door to be closed,, the plungers in cooperation with those catches will positively lock or hold the door in open position regardless of the relation between the door load and the opposing spring force. Conversely, in a closing operation the plungers need be retracted only until disengaged from the stop surfaces of the lower catches since they will automatically ride over the intervening obstructions along their paths of movement to closed position.

From the above detailed description it will beapparent that there has been provided an improved counterbalanced drop end door assembly, which, in combining the spring counterbalancer and a safety device, will positively hold the door in open position regardless of the then relative forces of the door load and spring counterbalancer and also safeguard against failure of the counterbalancer. It should be understood that the described and disclosed embodiment is merely exemplary of the invention and that all modifications are intended to be included that do not depart from the spirit of the invention and the appended claims.

Having now described my invention, 1 claim:

1. A counterbalanced drop end door assembly for a railway gondola car having a body and a drop end door bottom hinged to and swingable between sides of the body from a vertical closed position closing an end thereof to a substantially horizontal open position, said assembly comprising spring means for counterbalancing the load of the door during swinging thereof between open and closed positions, and safety means including latch means mounted on an upper portion of and having plunger means yieldably projectable laterally beyond the door, and spaced upper and bottom catch means fixed to and instanding from the car body in the path of movement of and sequentially engaged by said plunger means in a door opening operation for respectively stopping the door in partly open position and locking the door in open position.

2. A counterbalanced drop end door assembly according to claim 1, wherein the bottom catch means has downwardly facing stop surface means and ramp means leading downwardly thereto for automatically directing the plunger means into backing engagement therewith.

3. A counterbalanced drop end door assembly according to claim 2, wherein the latch means includes a pair of latches mounted in lateral alignment on opposite sides of the door and each having a laterally acting plunger normally spring urged beyond an adjoining side of the door during swinging thereof between open and closed positions, and the bottom catch means includes a pair of bottom catches fixed in lateral alignment to opposite sides of the car body and each automatically engageable with the adjoining plunger on swinging of the door to open position.

4. A counterbalanced drop end door assembly according to claim 3, wherein the upper catch means includes a pair of upper catches fixed in lateral alignment to the opposite sides of the car body and each spaced upwardly from the adjoining bottom catch along the path of swinging movement of the adjoining plunger and having a stop surface facing toward the adjoining end of the body and in an opening operation engageable with the adjoining plunger for releasably stopping the door in partly opened position.

5. A counterbalanced drop end door assembly according to claim 4, wherein the upper catches have ramps leading outwardly toward the stop surfaces thereof for automatically passing the plungers on swinging of the door from open to closed position.

6. A counterbalanced drop end door assembly according to claim 5, including a handle on each plunger for limiting projection and permitting retraction thereof respectively into and out of engagement with the catches engageable thereby.

7. A counterbalanced drop end door assembly according to claim 6, wherein the plunger of each latch projects inwardly into a depression in a front of the door, and open an ended tubular housing extending from the depression through an adjoining side of and fixed to the door slideably houses the plunger, the plunger has an open inner end or receiving a coil spring by which it is yieldably projected, said spring acts between the plunger and an abutment fixed in the depression inwardly beyond the housing, a guide pin fixed to and projecting outwardly from the abutment concentric with the plunger is received in the inner end of said spring, and the handle on the plunger is positioned and moves laterally between said housing and abutment.

8. A counterbalanced drop end door assembly according to claim 7, wherein each plunger is reinforced by a plug fixed in its outer end and pressed against by the spring. 

1. A counterbalanced drop end door assembly for a railway gondola car having a body and a drop end door bottom hinged to and swingable between sides of the body from a vertical closed position closing an end thereof to a substantially horizontal open position, said assembly comprising spring means for counterbalancing the load of the door during swinging thereof between open and closed positions, and safety means including latch means mounted on an upper portion of and having plunger means yieldably projectable laterally beyond the door, and spaced upper and bottom catch means fixed to and instanding from the car body in the path of movement of and sequentially engaged by said plunger means in a door opening operation for respectively stopping the door in partly open position and locking the door in open position.
 2. A counterbalanced drop end door assembly according to claim 1, wherein the bottom catch means has downwardly facing stop surface means and ramp means leading downwardly thereto for automatically directing the plunger means into backing engagement therewith.
 3. A counterbalanced drop end door assembly according to claim 2, wherein the latch means includes a pair of latches mounted in lateral alignment on opposite sides of the door and each having a laterally acting plunger normally spring urged beyond an adjoining side of the door during swinging thereof between open and closed positions, and the bottom catch means includes a pair of bottom catches fixed in lateral alignment to opposite sides of the car body and each automatically engageable with the adjoining plunger on swinging of the door to open position.
 4. A counterbalanced drop end door assembly according to claim 3, wherein the upper catch means includes a pair of upper catches fixed in lateral alignment to the opposite sides of the car body and each spaced upwardly from the adjoining bottom catch along the path of swinging movement of the adjoining plunger and having a stop surface facing toward the adjoining end of the body and in an opening operation engageable with the adjoining plunger for releasably stopping the door in partly opened position.
 5. A counterbalanced drop end door assembly according to claim 4, wherein the upper catches have ramps leading outwardly toward the stop surfaces thereof for automatically passing the plungers on swinging of the door from open to closed position.
 6. A counterbalanced drop end door assembly according to claim 5, including a handle on each plunger for limiting projection and permitting retraction thereof respectively into and out of engagement with the catches engageable thereby.
 7. A counterbalanced drop end door assembly according to claim 6, wherein the plunger of each latch projects inwardly into a depression in a front of the door, and open an ended tubular housing extending from the depression through an adjoining side of and fixed to the door slideably houses the plunger, the plunger has an open inner end or receiving a coil spring by which it is yieldably projected, said spring acts between the plunger and an abutment fixed in the depression inwardly beyond the housing, a guide pin fixed to and projecting outwardly from the abutment concentric with the plunger is received in the inner end of said spring, and the handle on the plunger is positioned and moves laterally between said housing and abutment.
 8. A counterbalanced drop end door assembly according to claim 7, wherein each plunger is reinforced by a plug fixed in its outer end and pressed against by the spring. 